Shoe sole



Sept. 13, 1955 w, GQIN 2,717,462

SHOE SOLE Filed March 27, 1953 INVENTOR. SANFORD W. 60m BY United States Patent 0 SHOE SOLE Sanford W. Goin, Gainesville, Fla.

Application March 27, 1953, Serial No. 345,205 4 Claims. or. 36-71) This invention relates to shoe sole construction, and more particularly, has reference to a shoe sole having a depressed area formed in the underside thereof, said area being so shaped, and the shoe sole being so proportioned as to the cross sectional configuration thereof, as to produce a highly effective arch action affording proper support under the metatarsal arch of the foot when pressure is exerted on the sole during standing or walking.

It has been observed that the soles of conventional shoes first show signs of wear in the area thereof underlying the central portion of the forward ball of the foot. In this connection, the natural cross section of the bottom of the average human foot, at a point near the forward ball of the foot, approximates an arch, and it is reasonable to assume that properly, weight exerted downwardly on the foot should be distributed between the pressure point behind the great toe, and the pressure point behind the fourth and little toe, with the portion therebetween being left unsupported.

The present invention is based on the assumption that if weight is distributed through the sole of the shoe at the same points intended by nature in the sole of the foot, then reinforcement is desirable at the points of pressure, with less material being required at the center, between said pressure points. It may be noted, in this connection, that the skin of the sole of a foot is thicker and tougher at the pressure points, that is, the balls of support, than at the center of the transverse arch of the foot.

In view of the above, the main object of the present invention is to form a shoe sole with a depressed, generally T-shaped area in the underside of said sole, at the vicinity of the transverse arch of the foot, with said sole being tapered in cross section toward the opposite side edges thereof, in such a manner as to create negative bending in the shoe sole when pressure is applied thereto, thus to curve transversely or bow the upper surface of the sole correspondingly to the transverse arch of the foot.

Another object of importance is to provide a shoe sole of the type stated in which the negative bending of the shoe sole will occur only when pressure is applied thereto, as in walking or standing, the shoe sole being otherwise adapted to bend to a normal position when not in use, in which normal position the upper surface of the shoe sole will be approximately fiat.

It is further proposed to provide a shoe sole construction as stated in which the design will cause the sole to wear longer than conventional soles, while at the same time permitting economies in the selection of materials.

Other objects will appear from the following description, the claims appended thereto, and from the annexed drawing, in which like reference characters designate like parts throughout the several views, and wherein:

Figure 1 is a bottom plan view of a shoe equipped with a sole formed in accordance with the present invention, the dotted lines indicating the outline of a foot supported upon said sole;

Figure 2 is a view partly in side elevation and partly in longitudinal section, showing the shoe and sole;

Figure 3 is a transverse sectional view on line 3-3 of Figure 2, the sole appearing as it would when downward pressure is applied thereagainst during standing or walking; and

Figure 4 is a view similar to Figure 3, showing the sole as it appears when no pressure is exerted thereagainst.

The reference numeral 10 has been applied generally in the drawing to a conventional shoe, havingan upper 12. The shoe is equipped with a sole designated generally by the reference numeral 14, said sole constituting the present invention and being formed, in its underside, with a longitudinal groove 16 merging at its front end into a transverse groove 18.

A human foot has been designated by the reference letter F, and as will be noted frim Figure 1, the forward edge of the front ball of the foot is curved from side to side of the foot, with the midlength part of said curved front. edge portion of the ball being-directed forwardly, toward the toes.

The groove 16, as will be noted from Figure 1, is preferably straight from end to end thereof, and extends midway between the opposite sides of the front ball of the foot, from the back edge of said ball to the front edge thereof. At its front end, groove 16 merges into the midlength portion of the transverse groove 18, said groove 18 being widest at its center, and'tapering toward its opposite ends 20.

As will be noted, the groove 18 is curved from end to end thereof, in approximate correspondence with the curvature of the front edge of the ball of the foot, and it is also to be noted that the back edges of the tapered ends 20 of said groove 18 are extended in approximate alignment with the forwardly bowed or curved front edge of the ball. The forwardly bowed or curved leading edge of transverse groove 18 follows, generally, an imaginary line drawn along the bases or back edges of the pads of the several toes.

Referring now to Figures 3 and 4, it will be seen that in combination with the grooved arrangement illustrated in Figure l, I provide a particular cross sectional shape in the shoe sole, wherein said sole is thickest medially between its opposite side edges, and is tapered from said thickened midwidth portion in the direction of the respective side edges. Normally, when the foot is at rest and no downward pressure is being exerted against the shoe sole, the upper surface of the shoe sole is of plane formation when viewed in cross section (Figure 4), the underside of the shoe sole being inclined upwardly from the thickened midwidth portion toward the respective side edges of the sole.

When, however, downward pressure is exerted on the shoe sole, as for example during standing or walking, the pressure will be transmitted to the shoe sole at transversely spaced pressure points of the sole of the foot, said pressure points being located at opposite ends of the metatarsal arch of the foot.

This action is shown to advantage in Figure 3, wherein it will be seen that the opposite sides of the foot are lower than the midwidth portion of the foot.

T he exertion of downward pressure upon the tapered side edge portions of the shoe sole, in this manner, will create a negative bending moment in the sole, tending to flex the sole transversely from the position shown in Figure 4, to the position shown in Figure 3. As a result, the upper surface of the sole will now be bowed upwardly medially between its opposite side edges, that is,

saidupper surface of the sole will be transversely curved in approximate correspondence to the curvature of the metatarsal arch. Meanwhile, the underside of the sole will be of plane formation, so as to lie fiat against a supporting surface S.

The grooved formation shown in Figure l cooperates with the transverse or cross sectional configuration of the shoe sole, to facilitate the flexure of the sole in the manner described above. This is so because the longitudinal grooving of the shoe sole defines a thinner midwidth portion on the sole, at the exact point at which the flexure is to occur. Further, the transverse grooving of the shoe sole prevents the shoe sole from engaging thesupporting surface at locations to which, desirably, pressure is not to be applied. In other words, the construction illustrated is one that causes the shoe sole, after flexing thereof, to take the pressure transmitted from the foot at the opposite ends of the metatarsal arch, rather than in the area between said ends of the arch.

I believe that quite possibly, the construction illustrated and described could be embodied in a shoe sole attachment, to be cemented or otherwise secured to the underside of a conventional shoe sole, although more usually, the design would be incorporated in new soles.

It is believed apparent that the invention is not necessarily confined to the specific use or uses thereof described above, since it may be utilized for any purpose to which it may be suited. Nor is the invention to be necessarily limited to the specific construction illustrated and described, since such construction is only intended to be illustrative of the principles of operation and the means presently devised to carry out said principles, it being considered that the invention comprehends any minor change in construction that may be permitted within the scope of the appended claims.

What is claimed is:

l. A shoe sole having, at that part thereof disposed below the metatarsal arch of the foot, a cross sectional shape wherein the upper surface of the sole is normally planiform and the underside thereof is inclined upwardly from the midwidth portion of the sole toward its opposite side edges, said sole being flexible transversely to create a negative bending moment responsive to the application of pressure thereagainst by the foot at opposite ends of the transverse metatarsal arch, tending to bow said upper surface of the sole into correspondence with the curvature of the transverse metatarsal arch, while simultaneously flexing the underside of the sole into a planiform condition.

2. A shoe sole having in its underside a T-shaped concavity, one leg of which is extended longitudinally of said shoe sole and merges into the other leg, said other leg having front and rear side edges both of which are curved from end to end thereof into correspondence with the leading edge of the ball of a foot.

3. A shoe sole having in its underside a T-shaped coucavity one leg of which is formed as a relatively narrow, straight groove extended longitudinally of the shoe sole medially between the opposite side edges thereof, the other leg of said concavity being in communication with the first leg intermediate the ends of said other leg, said other leg being of substantial width in the area of its midlength part, and said other leg having front and rear. side edges both of which are curved from end to end.

thereof into correspondence with the curvature of the leading edge of the ball of a foot.

A shoe sole having, at that part thereof disposed slow the metatarsal arch of the foot, a cross sectional shape wherein the upper surface of the sole is normally planiform and the underside thereof is inclined upwardly from the mid-width portion of the sole toward its opposite side edges, said sole being flexible transversely to createa negative bending moment responsive to the application of pressure thereagainst by the foot at opposite ends of the transverse metatarsal arch, tending to bow said upper surface of the sole into correspondence with the curvature of the transverse metatarsal arch, while simultaneously flexing the underside of the sole into a planiform condition, said underside of the sole having formed therein a generally T-shaped concavity, one leg of. which is extended longitudinally of the shoe sole and the other leg of which is extended transversely of the sole and is curved from end to'end thereof into correspondence with the leading edge of the ball of a. foot, said concavity decreasing the thickness of the shoe sole along the midwidth portion thereof to facilitate transverse flexure of the sole, the curved leg of said concavity holding the underside of the sole out of engagement with a supporting surface over an area extending between said ends of the transverse metatarsal arch.

References Cited in the file of this patent UNITED STATES PATENTS 379,732 Busby Feb. 18, 1908 1,541,234 McKnight et a1. June 9, 1925 1,636,044 Connelly July 19, 1927 1,680,147 Gilowitz Aug. 7, 1928 

